Method of charging containers with carbon dioxide



NOV. 1, w, H FREYGANG METHOD OF CHARGING CONTAINERS WITH CARBON DIOXIDE Filed May 7, 1930 NWQQ'Q qf/v: L

Qvwemtoz Wd/far H. Fre qd lj $3M h/s SHIN/140135 g la Patented Nov. 1, 1932 UNITED STATES PATENT OFFICE WALTER H. FREYGANG, 0F WEEHAWKEN, NEW JERSEY, ASSIGNOR TO WALTER KIDDE & COMPANY, INC., OF NEW YORK, N. Y., A CORPORATION OF NEW YORK METHOD OF CHARGING CONTAINERS WITH CARBON DIOXIDE Application filed May 7,

This invention relates in general to improvements and apparatus by means of WlllCh carbon dioxide containers or tanks such as are used for example in fire extinguishers can be recharged with the proper amount of carbon dioxide from commercial cylinders of carbon dioxide.

A further object of this invention is the provision of apparatus by means of which such containers or tanks may be filled with the required amount of carbon dioxide under the correct pressure from commercial cylin-' ders without returning the containers or tanks to the filling station.

A still furth r object of this invention is the provision of apparatus of this nature by means of which the containers or tanks may be rapidly and efficiently charged without undue expense and without Waste of gas from the commercial cylinders.

A still further object of theinvention is the provision of relatively simple apparatus by means of which these objects may be readily .attained.

A still further object of the invention is the provision of apparatus having a safety blowout disc in the delivery line by means of which excessive pressure may be relieved without damage to any of the apparatus.

A still further object is the provision in the piping system of a strainer through which the gas must pass before reaching the container or tank being filled to remove foreign material and the like therefrom.

An additional object is the provision of means by which it may be ascertained when the correct amount of carbon dioxide has been forced into the container or tank to be charged.

These and other objects as will appear from the following disclosure are secured by means of this invention.

This invention resides substantially in the combination, construction, arrangement and relative location of parts, all as will be described in greater detail hereafter.

Referring to the drawing;

Figure l is an elevational View of the apparatus of this invention showing some parts in vertical cross-sectional view;

1930'. Serial No. 450,412.

Figure 2 is another detail view showing the strainer construction and the connections to the valve of the commercial container As is well known, carbon dioxide, which is a highly eificient agent for the purpose, is now extensively used in fire extinguishing apparatus. While carbon dioxide for large fire extinguishing systems is usually supplied in special large containers, for portable extinguisher use and for small built-in installations it is supplied in relatively small cylinders which contain a suflicient amount for the particular purpose in hand. When it becomes desirable to fill or refill such small containers or cylinders, it has heretofore been generally necessary to return these tanks to central carbon dioxide producing plants where they may be refilled. Such plants are relatively few in number and are widely distributed over the country, so that it is an expensive and slow procedure to return these small containers for refilling in the usual manner. On the other hand, large commercial tanks are obtainable at the various central carbon dioxide producing plants throughout the country, and it would be highly advantageous to be able to efficiently and rapidly recharge the small containers from the large commercial containers, which could be transported from the central plants so as to be available at numerous distributing points throughout the country. At such distributing points there would be kept a reserve of large commercial containers sothat the small tanks could be filled therefrom in an efficient and inexpensive manner.

Since the carbon dioxide is contained in these large tanks in liquid form under a considerable pressure, it would appear to be an exceedingly simple process to connect the smaller tank to the larger tank. and. fill it therefrom. Such, however, is not the case. In order to get anywhere near the proper amount of carbon dioxide in the smaller c0n tainers it has been found necessary to first charge the smaller tank from the larger tank and then permit the gas to escape from the smaller tank into the atmosphere so as to effect a cooling of the smaller tank by reason of the expansion of the carbon dioxide discharged from the smaller tank. The small tank is again rechar ed and discharged and finally charged a thir time before it will take in the pro r amount of carbon dioxide. As a result 0 such method the small tank must be twice discharged into the atmosphere, re-.

sulting'in a very large loss of carbon dioxide as well as a loss in time consumed in these operations It will, of course, be understood that the carbon dioxide is usually maintained in cylinders under such pressures, that below the critical temperature of carbon d 1- oxide, which is 88.4 F., the carbon dioxide 1s mostly in liquid'form, the proportion of liquld increasing with decrease in temperature. It will, therefore, be understood that when the small cylinder is sutliciently cooled by the above method, a greatenproportion of liquid will be transferred and it is then possible to fill it with the desired amount.

The purpose of the apparatus of the present invention is to avoid the above-mentioned dificulties and to provide a simple assembly by means of which the smaller containers ma be charged from'the large containers wit out any loss of gas and with only one charging operation. This apparatus is, of course, much simpler than the apparatus employed in the large gas generating plants and can, therefore, easily attain wide distribution so as to be more available for use in charging the small containers.

The apparatus involved is shown in the drawing as comprising a supporting base 1, to which is secured a driving electric motor 2. The current leads at 3 pass through the switch box 4 and through nipple 5 to the motor. The motor is provided with a spur gear 6 which meshes with the large driving gear 7 within the casing 8 of a pumping apparatus. Theshaft on which gear is suported is provided with the eccentric 9 which is connected to the cross head 11 by means of the connecting rod '10. The cross head 11 oscillates within the vertical casing 12 and in turn is connected by means of piston rod 13 extending through the packing gland 14 with the piston 16 within cylinder 15. Piston 16 is provided with a number of ports 17 extending all the way therethrough, which ports are controlled by means of a valve 18 which slides on a bolt 19 secured to the piston. A spring is provided as shown, for holding the valve 18 on its seat and closing ports 17. 'The upper end of cylinder 15 is closed by a plate 20 which has a port extending therethrough, which port is normally closed by the ball check valve 21. On top of plate 20 is secured a head 23 provided with a recess within which the ball check valve 21 is mounted, as well as the spring 22 for holding the check valve seated.

I g The upper end of the head isprovided with a transverse passage 25 which is in communication with the cylinder 15through the passages 24 in form at a temperature of minus 57 C.

the head when the ball check valve is unseated. The right hand end of .passage 25 is closed by means of a thin safet 'disc 27 which is held on a gas tight seat ymeans of the plug 26'which has a hole therethrough. The safety disc 27 is made of thin metal of such strength that it will burst when the redetertice to supply the large commercial containers either with or without a syphon tube. If the container employed with this apparatus has a siphon tube it is supported in its usual vertical position as illustrated in Fig. 1, but if it has no syphon tube, it will be connected to pipe 50 in an inverted position. The reason for this is that most of the carbon dioxide is in liquid form which it is desired to deliver to the small container with as little of it returning to gas form as possible.

i The reason for employing the commercial cylinder without a siphon tube in an inverted position will be found in Rustige United States Patent No. 1,335,394. Very briefly, it

has been found that when a commercial con-' tainer without a siphon tube is employed in an erect position, the discharge from the container takes place from the gaseous space overlying the liquid in the container, and as the discharge is taking place, some of the liquid inthe container evaporates to supply the additional gas which is removed and this vaporization takes place so quickly that the heat required for the vaporization is not removed from the surrounding atmosphere, but from the liquid within the container, with the result that the liquid is reduced to so low a temperature that it freezes into a solid mass of carbon dioxide snow, which first beginsIto however, a siphon tube is employed in the container, or if the container having no siphon tube is emptied in an inverted position, the liquid portion of the contents will be removed first with practically no opportunity for expansion, so that freezing-up of the liquid in the cylinder, as well as the valve passages, is not encountered. Therefore, the reason for employing the commercial container without a syphon tube in an inverted position is to remove the liquid portion of the contents and thus avoid freezing and clogging of the valve passages and the connecting pipe line.

There is still another reason for removing the liquid portion of the contents rather than the gaseous portion, and that is that, except above the critical temperature of carbon dioxide, the density of the gaseous portion is so little that the particular apparatus which is employed will not pump the gas. Of course, the pump could be designed to transfer gas, but it will be understood that the pumping operation would have to extend over a much longer period of time to pump the same weight of a less dense medium.

The lower end of cylinder 15 is provided with a port in which is secured the nipple 36. A flexible hose 38 is secured at one end to the nipple by the nut 37, and at its other end by nut 39 to a short length of pipe 50. This pipe is secured by nut 40 to a coupling member 41 which has a portion thereof in the form of a nut by means of which it is secured to the threaded extension of the valve 44 of the large commercial container 46. The valve 44 is provided with the stem 45 by means of which it is operated. This large container 46 is the container from which it is desired to fill the small fire extinguishing container 35 with the desired amount of carbon dioxide. At 47 is diagrammatically illustrated a scale on which the smaller container rests while being charged and by means of which it is possible to tell when the small container is fully charged.

As shown in Fig. 2 the delivery line from the large commercial container which is used as a supply source is provided with a strainer 51 for removing foreign material from the carbon dioxide as it passes therethrough.

In the operation of the apparatusthe large container 46 is coupled to the intake pipe of the compressor and the small container is in turn coupled to pipe 33. The valve 34 of the small container is opened by means of the lever 36'. Likewise the valve 44 of the large container is opened by the application of a similar lever to the valve stem 45. In practice the compressor is first started running before the valve 44 is opened. Valve 32 having also been opened and with the compressor running, the small container 35 is filled until the scales indicate that the desired amount is therein. Valve 32 is then closed, the compressor being stopped and after valve 34 is closed the tank 35 is disconnected from the line. During the operation of the apparatus, if for any reason the pressure in this system exceeds the predetermined desired amount the blow-out disc 27 will fracture thus preventing any injury to the apparatus. It is preferable in apparatus of this type to supply the carbon dioxide to the lower end of cylinder 15 and to construct the piston with ports and a valve as shown, so that the carbon dioxide is delivered to the space above the piston during the full non-pumping stroke thereof. During the upstroke valve 18 is seated and the pressure created in the cylinder is sufficient to unseat the check valve 21 and force the carbon dioxide into cylinder 35.

For purposes of description of the principles of this invention reference has been made to small cylinders to be charged from large commercial cylinders. Those skilled in the art will appreciate that this invention is not in any sense so limited in practical use. The cylinder, tanks, or container to be filled may be of any size, shape and construction either with or without a syphon tube. If they have no siphon tube, a special valve or its equivalent may be used to insure delivery of liquid therefrom. A container without a syphon tube or its equivalent is not satisfactory for use in fire extinguishing apparatus for wellknown reasons. The standard or commercial cylinders referred to as the source of carbon dioxide are the type used in the soda water industry without siphon tubes but not necessarily so. Where the container to be filled is smaller than the commercial cylinder as a source, only one commercial cylinder need be used but where it is larger a bank of commercial cylinders may be used.

From the foregoing disclosure it will be apparent that I have devised a system of the type described embodying certain principles of construction and operation which may be embodied in other physical forms, without departing from the spirit and scope of the invention. I do not, therefore, desire to be strictly limited to the disclosure as given in the drawing and specification, but rather to the scope of the invention as it is defined in the appended claim.

What I seek to secure by United States Letters Patent is:

The method of transferring liquid carbon dioxide under its own vapor pressure from a supply container to another container through an intermediate chamber, which consists in delivering liquid carbon dioxide under its own vapor pressure from the supply container to the receiving container through the intermediate chamber, isolating the intermediate chamber from the supply container, increasing the pressure in said chamber above that in the receiving container to cause flow of carbon dioxide from said chamber to said receiving container, isolatingsaid chamber from said receiving container, decreasing the pressure in said chamber to below that in the supply container, so that the isolation of said chamber from the supply. container is removed and the flow of liquid carbon dioxide under its own vapor pressure into said chamber is reestablished, and repeating the cycle of operations.

In testimony whereof I have hereunto set my hand on this 1st day of May. A. D.. 1930.

WALTER H. FREYGANG. 

